Two simple and sensitive spectrophotometric and spectrofluorimetric methods have been
described for the determination of trimetazidine dihydrochloride in bulk and dosage forms. The
first method depends on ion pair complexation between the cited drug with two dyes; tropaeloin
000 and methyl orange in aqueous medium. All variables affecting the formation of complex
were studied and optimized. The coloured products of the drug with tropaeloin 000 and methyl
orange were measured at 490 nm and 422 nm respectively, after extraction with chloroform.
Beer's law was obeyed in the concentration ranges 4-20 μg ml-1 and 2-12 μg ml-1 for tropaeloin
000 and methyl orange respectively. The spectrofluorimetric method depends on the
condensation of malonic acid and acetic anhydride under the catalytic effect of trimetazidine
dihydrochloride. The condensation product gave two emission maxima measured at 452 nm (λex
393 nm) and 470 nm (λex 428 nm). Variables affecting this condensation reaction were studied
and optimized. At both maxima of emission good correlation was observed in the range 40-200
ng ml-1. The proposed methods were applied successfully for the determination of the cited drug
in tablet dosage form without interference from common encountered additives. Percentage
recoveries ranged from 98.9% to 99.7% in bulk and 96.9% to 98.3% in tablet dosage forms
analysis.